Imaging of biological tissues and organs assists doctors in both diagnosis and treatment. A variety of medical techniques which are suitable for imaging biological tissues and organs are known. These include traditional x-rays, ultra-sound, as well as magnetic resonance imaging (MRI), and computerized tomography (CT). A variety of dyes used in medical imaging have also been described including radio opaque dyes, fluorescent dyes, as well as, colormetric dyes (see e.g., U.S. Pat. Nos. 5,699,798; 5,279,298; 6,351,663; and 6,915,154 and U.S. patent application Ser. Nos. 10/619,548 and 10/365,028). Imaging techniques and systems using fluorescent dyes have been described for the heart and eye (see, U.S. Pat. No. 5,279,298; U.S. patent application Ser. No. 10/619,548, which is incorporated by reference in its entirety). Some dyes can serve both an imaging function, as well as a therapeutic function (see, e.g. U.S. Pat. No. 6,840,933).
Organ transplant is one area in which imaging methods and systems would prove useful. The demand for organ transplant continues to grow. The combined number of solid organ transplants in the US alone, is approximately 18,000 per year. Specifically the combined numbers for years 1997 and 1998 were: 1,692 lung transplants, 4,409 heart, 7,502 liver, 326 pancreas, 1,803 pancreas and kidney, and 20,956 kidney transplants (see, e.g., The U.S. Organ Procurement and Transplantation Network and the Scientific Registry of Transplant Recipients Annual Report, 2004).
Transplant procedures involve anastomosis. These anastomoses may be between, for example, two vessels, vessels and duct(s), two ducts, or vessels and ureter(s), two parts of a ureter, or the ureter and bladder. As such, solid organ transplant procedures would benefit from the preoperative assessment of the patency of vessels, ducts, and ureters of the donor organs, and intra-operative and postoperative verification of anastomoses and the patency of blood vessels, ducts, and ureters of the transplanted organs, as well as other recipient blood vessels, ducts, and ureters. It would be particularly useful to provide real time, i.e. intra-operative visual confirmation regarding the verification of anastomoses and patency of vessels, e.g. vasculature. Traditional intra-operative imaging techniques, are frequently ineffective, expensive and inconvenient. The need therefore exists for methods and systems for imaging vessels associated with solid organ transplants which are safe, effective, convenient and cost effective.